Wave | Time period | Survey mode | Non-smokers | Smokers | Total |
1 | July 2001 | Telephone | 463 | 442 | 905 |
2 | December 2001 | Telephone | 484 | 422 | 906 |
3 | December 2002 | Telephone | 459 | 452 | 911 |
4 | December 2003 | Telephone | 956 | 843 | 1799 |
5 | June 2004 | Telephone | 962 | 835 | 1797 |
6 | December 2005 | Web | 1609 | 366 | 1975 |
7 | June 2006 | Web | 1994 | 466 | 2440 |
8 | December 2006 | Web | 1512 | 454 | 1966 |
9 | June 2007 | Web | 1403 | 357 | 1760 |
10 | December 2007 | Web | 982 | 257 | 1239 |
11 | June 2008 | Web | 797 | 231 | 1028 |
Note that the web-respondents in waves 6 through 11 are not unique.